In the current Cell process, PI Inkjet coating has the features that no APR plate is needed (which is used in the process of the existing glass substrate which is small), the speed of PI Coating high and the production capacity is high; however, it is difficult to control the uniformity of PI Coating, especially on the periphery of the cell, and defects are mainly centralized on an array substrate (the dispersal uniformity of the PI liquid in contact with a metal is not as good as the dispersal uniformity of PI liquid on an organic film, therefore the defects of PI coating are mainly centralized on the array substrate, other than on the color filter substrate), thus PI Coating-related defects tend to occur. As shown in FIG. 1, an array substrate 1 and a color filter substrate 2 are encapsulated via a sealant 3, an orientation layer 4 is formed on the array substrate 1 by an orientation solution, and since a metal layer is arranged on a non-display area on the periphery of the array substrate 1, via holes are formed and the density of the via holes is larger than that of a display area, the orientation solution disperses nonuniformly on the periphery of the array substrate, and the defects becomes more serious. How to overcome the above defects becomes an urgent problem in the process of an orientation film.